Update and rename index.md to index.md Update OVERLAY ref

index.md → index.md Update OVERLAY ref

@@ -15,7 +15,9 @@ This website gives a brief overview of our [HOLMS library](https://github.com/HO
   J Autom Reasoning 67, 29. DOI:[10.1007/s10817-023-09677-z](https://doi.org/10.1007/s10817-023-09677-z) (Open access)
 - Antonella Bilotta, Marco Maggesi, Cosimo Perini Brogi, Leonardo Quartini (2024)<br/>
   ***Growing HOLMS, a HOL Light Library for Modal Systems***.<br/>
-  (In preparation)
+  [OVERLAY 2024](https://overlay.uniud.it/workshop/2024/) - 6th International Workshop on Intelligence and fOrmal VERification, Logic, Automata, and sYnthesis <br/>
+  28 and 29 November, Bolzano (Italy).<br/>
+  [Download](https://overlay.uniud.it/workshop/2024/papers/paper5.pdf).
 
 ## Contributors